Edwaed s



(No Model.) v E. S. T. KENNEDY.

STEAM BOILER.

Patented Nov. 10, 1885.-

FIE/f .WITNEESES UNITED STATES- PATENT OFFICE.

EDWARD S. T. KENNEDY, OF NEW YORK, N. Y.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 329,911, dated November10, 1885.

Application filed August 28, 1885. Serial No. 175,545.

T0 or, whom it may concern.-

Be it known that I, EDWARD S. T. KENNEDY, a citizen of the United Statesof North America, and a resident of the city, county, and State of NewYork, have invented a new and useful Improvement in Steam-Boilers, ofwhich the following is a specification.

The object of this invention is to construct a boiler of the porcupinetype possessing better Water-circulation and greater durability thanthose ordinarily in use. In the or dinary porcupineboiler the tubesradiating from the central cylinder are all of the same length. They allextend to/within a very short distance from the boilerinclosing shell orwall. This method of construction is correct as far as concerns thehigher planes or series of tubes, as they should be as long as possiblein order to intercept the heat on its upward passage; but as regards thelower series or planes of tubes nearer the fire, it is found in practicethat they may be of too great length for securing good circulation atall times or for durability, for the intense heat of the lower part ofthe combustionthe fire is urged,) impinging on the extremities of thetubes, often repels the water therein, thereby not only preventingproper circulation, but causing said tubes to be burned and seriouslyinjured.

These objections are avoided by my invention, which consists of acentral upright cyl- 1nder set on a suitable support, preferablyarranged in the bottom of the ash-pit. and pro vided with a series ofradiating tubes closed at their outer ends, set staggering in successiveplanes, one above another, the tubes in the lowest series being theshortest, and the tubes increasing in length in each successive seriesupward for a considerable distance above the grate.

Figure 1 is a vertical sectional elevation of my improved boiler. Fig. 2is a plan of the same on line a; at, Fig. 1.

Reference is to be had to the accompanying drawings, forming part of thespecification, in which similar letters of reference indicatecorresponding parts in both the figures.

In the drawings, A represents the upright boiler-cylinder, extendingdown through the ash-pit and supported on the bottom thereof, so as tohave the firmest possible foundation, and so that the lower portion ofthe cylinder (N0 model.)

shall be in a comparatively cool place to properly exercise the functionof a mud-drum.

0 represents the boiler-inclosing shell or walls. The space inside theshell or walls from the grate-bars D to the hood E forms thecombustion-chamber.

From the central cylinder, A, series of tubes a a, closed at their outerends and communieating at their inner ends with the interior of theboiler cylinder, radiate in horizontal planes, one above the other. Thetubes of the lower series or plane nearest the grate-bars are shorterthan any of the others. Those of the next highest series or plane aresomewhat longer than those of the first, and in each succeeding seriesor plane the tubes are still longer than in the series next below, untila suitable distance above the grate is reached, as indicated in Fig. 1,and above that point all the tubes in the succeeding series or groupsare of equal length. Thus it will be seen that the several lower seriesor groups of radiating tubes would be inclosed in outlines representingthe frustum of an inverted cone, the lower groups or series decreasingin diameter downward.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. A boiler constructed, substantially as hereinshown and described, of an upright cen tral cylinder provided withseries or groups of tubes radiating therefrom in successive planes, oneabove another, each of the several lower series or groups of which islonger than the group next below, so that the several lower groups couldbe inclosed in outlines representing the inverted frustum of a cone, asset forth.

2. The combination, with the vertical boiler-cylinder A, adapted to besupported on the bottom of the ash-pit, of the upper series or groups ofradiating tubes, a, of equal length, and lower tube groups or seriesdecreasing in diameter downward, as set forth.

In testimony that I claim the foregoing as my invention I have signed myname, in presence of two witnesses, this 16th day of July, 1885.

EDWARD S. T. KENNEDY.

